Wheelbuilders help - does it really matter if I lace to the "wrong" rim eyelets?

I'm lacing an A119 rim, where the eyelets have a small but definite offset to one side or the other, but they're all flat in the rim. Does it actually matter all that much if I lace to the ones furthest from the hub flange, rather than the closest ones as you'd normally do? It would enable me to have the valve hole in the right point in the spoke pattern, which isn't really all that important and I wasn't going to bother with, but then I figured that actually which eyelet I laced to might not be all that important either. After all at one point Shimano made some wheels where the spokes were attached to the opposite sidewall of the rim (citing an improvement in stiffness from doing so).

You probably have, but just haven't noticed - which may answer the question itself. The offset is only 1 or 2mm to each side, and you have to look pretty hard to see which way. I don't think it makes any difference at all to the spoke length required - though if anything it will help slightly as the spokes I have are on the long side (I'm reusing spokes - ironically the rim I'm replacing had a smaller ERD, so the spokes were even more too long for it).

If you don't, then the wheels will be unbalanced and as soon as you reach 20mph they will explode in a deadly fireball. Kittens will be severely injured, possibly killed and at least 4 children's faces will be at risk. Ignore this advice at your peril!

It will probably make no difference but the rim will probably be slightly unstable. The centre bit of a rim will be under stress. The offset will provide a slightly greater area over which to distribute this stress. Buy lacing it incorrectly, the area to be stressed will be narrower but will gave the same levels of stress applied to it,

In an extreme situation, the rim would be more likely to twist due to this narrower zone.

Try balancing something on 2 fingers spread apart, now move your fingers in and try balancing the same object. It's less stable.

It probably will never happen but I know if it was one if my wheels it would annoy the crap out if me until I relaced it.

I've done it wrong a few times, my excuse being that I was pissed when I built them. Empirical evidence suggests it makes no real world difference. One I know of is still going strong over 15 years later.

As a regular wheelbuilder I'd like to re-phrase the original question...

I've built my first set of wheels and realised that I've gone to the wrong side ofset on the rim... Have I really got to unlace the whole thing and re-do it or will it be O.K?

Congratulations on your assumption. Completely utterly wrong on all points, but well done anyway.

I explained in my OP the reason for wanting to do this - it enables me to have the valve hole in the normal place. A fairly unimportant point, but something I'd prefer, and if lacing the rim the "wrong" way is equally unimportant then I might as well do that.

If it helps you to understand the need to do this, the hub I'm using only has the spoke holes countersunk on one side, so I don't have complete freedom on how I lace the spokes in the hub, and the way the holes are offset is the wrong way round for the rim. As an experienced wheelbuilder have you ever had to build a wheel with a hub which only has holes countersunk on one side?

FWIW I've built about 10 sets of wheels, some of which have been going strong for over 10 years, and I've not yet laced to the rim on the wheel I'm building at the moment, just considering my options.

Interestingly the Open Pro diagram emphasises the angle of the hole where as for the Open sport and A119 there's an almost imperceptible cant to the eyelet grommet.

Thanks for the research and congratulations on managing to navigate the Mavic website. I don't think there's a real difference between Open Pro and Open Sport (I've got wheels I've built with both), just that the difference is more obvious with the double eyelet in the pro.

I guess I am slightly concerned about losing strength, as I'll have about twice the load on this as on a normal wheel.

This might be obvious to people less stupid than me, but the countersinking is not for the spoke heads, it is for the spoke bend, ie. the head of the spoke should go into the hub on the side opposite to the countersinking. Not knowing that can lead people to thinking that their hub and rim don't match. See on here:

Also, I rode a couple of unicycles with terribly built wheels (one built by Dave Mariner, with the wrong length spokes (way too long), one Pashley with rubbish spokes and built a bit loose). They lasted for years before self-destructing. So I suspect using the wrong lacing will be fine. Having said that, I never really got on with a narrow rim on a unicycle, even for road. Massively preferred a wide rim.

This might be obvious to people less stupid than me, but the countersinking is not for the spoke heads, it is for the spoke bend

Yep, I've got them that way round, but I don't think it's at all obvious - though I don't think it would make any difference if I had all the spokes the wrong way round. The wheel actually had the elbows in the countersunk side on one flange and the heads in the countersunk holes on the other flange when I got it! Thanks very much for that link, it confirms a lot of my thinking.

The original build of this wheel was rubbish - apart from having the spokes the wrong way in one flange, the spokes were also far too long (I think they calculated for 32 spokes which seems to be the default with spoke calculators, as they're exactly the right length for that - unfortunately the hub is 36 hole). That resulted in very low tension - the last time I rode it a couple of the spokes went completely slack which really didn't help much with the handling. I'm not convinced a wide rim makes that much difference with a road tyre at fairly high pressure - I have one 29er with a wide rim, and this one with a narrow one (it came with a 729, which is the same width as the A119) to compare, and they feel pretty similar when I'm using the same gear ratio on both.

I'm not quite sure what you mean by "the normal place" - usually the valve hole has spokes angling away from it, and the direction of the holes on the rim won't affect this.

By "normal place" I mean with all the spokes angling away as you mention. See the "boxing the valve" section in joe's link - if I build the wheel the way I want to in all other respects I have no choice but for the valve to be in one of the positions labelled "wrong". There's a bit of discussion of my issue in the "Symmetric and Asymmetric Wheels" section of that link. They suggest there that if you can't get everything the correct way you should build asymmetric, however IMO that is the worst compromise in this case as it means the rim will move laterally under power/braking (unlike a bike hub I'd expect equal torque transmission on both sides). Hence I'm left with the choice of either not boxing the valve or not conforming to the rim polarity.

As mentioned above the original wheel build was rubbish - it was also asymmetric and didn't box the valve, hence I already know that having the valve in the wrong place in the spoke pattern isn't that big a deal. AFAIK from earlier conversations you own one of these hubs, ben - I think I've given enough hints by now for you to have worked it out - I'm curious how your wheel build on one is.